1. Field
The invention is concerned with methods of utilizing, to economic advantage, sponge metal fines such as are inevitably produced during crushing of a sponge metal regulus to produce particle sizes that can be pressed into sponge metal compacts.
2. Description of the Prior Art
The highly pyrophoric fines that inevitably result from the crushing of sponge metal, such as a regulus of zirconium and/or hafnium sponge metal produced in the reduction of the zirconium and/or hafnium tetrachloride powder resulting from chlorination of zircon sand in the process of producing relatively pure zirconium and/or hafnium metal, are normally burned to produce zirconium and/or hafnium oxide and are then added to the chlorination step of the overall process. However, this way of getting rid of these hazardous fines does not represent a recovery of their potential economic value.
In the co-pending application of Abodishish, Wahlquist, and Lopez, Ser. No. 07/437,948, filed Nov. 17, 1989, held under common ownership with the present application and in which one of the joint inventors, Randy W. Wahlquist, is a joint inventor here, such sponge metal fines are processed in a special vacuum distillation operation resembling the usual treatment of zirconium and/or hafnium sponge in a vacuum distillation furnace to remove magnesium and magnesium chloride, but involving lowering the usual charge-melting temperature in the furnace to below the melting point of the magnesium and magnesium chloride components of the furnace charge so that these components solidify about the sponge fines, whereupon furnace temperature is increased to an extent sufficient to vaporize the magnesium and magnesium chloride and to sinter the sponge fines into a sponge regulus which can be further processed in the usual manner.